Camera



All@ 18, .1942- A. H. COHEN 2,293,195

CAMERA Filed sept. 23, 1939 5 sheets-sheet 1 AL V/N H. COHEN T :l gi

Aug.1s, 1942.

A. H. col-IEN 2,293,195

CAMERA Filed sept. 25, 1939 5 sheets-sheet s INVENTOR ALV/N H. COHENATTOR Y Aug- 18, 1942- A'. H. COHEN .2,293,195

CAMERA Filed Sept. 25, 1939 5 Sheets-Sheet 4 i+1? Tlcll.

INVENTOR ALv/N H. COHEN BY M g ATTO R N EY Aug. 18, 1942. A. H. COHEN2,293,195

,CAMERA Filed sept. 2:5, 1959 5 sheets-'sheet 5 lNvEN-ron ALV/N H. COHENPatented Aug. 18, 1942 CAMERA Alvin H. Cohen, New York, N. Y., assignorof onehalf to Frederick L. Katz, New York, N. Y.

Application September 23, 1939, Serial No. 296,216

11 Claims.

My present invention relates generally to cameras, and has particularreference to certain improvements in a camera of the kind which isillustrated and described in my copending patent application Serial No.282,332.

The general objects are substantially the same as those set forth insaid pending application. I aim to provide a camera whose operation isgreatly simplified, and which functions reliably and uniformly atmaximum efficiency. The structure is of such a character that there is adefinite automatic correlation between the intensity and quality of thelight that enters the camera, the actinic sensitivity of the film, andthe effective shutter speed.

The present improvements are primarily intended to further simplify themode of use of the camera, and to widen its range of utility.

One of the present improvements provides for automatic film advancement,kthus further simplifying the mode of operation. In accomplishing thisobject, I am also enabled to make certain improvements in the filmmagazine or cassette, whereby it constitutes a complete selfcontainedlight-tight unit capable of independent handling. In accordance with thepresent invention, this unit is adapted to be removably inserted intothe camera body with a minimum of effort, and adapted to be properlypositioned and rendered operative by a simple rexteriorly controllablemeans.

It is a feature of the present invention to provide a vfilm cassettewhich comprises, within itself, a feeding reel, a take-up reel, and amotor urging the film from one reel to the other. Means are provided forrestraining the motor at all times except when film advancement iscalled for.

Another of the present improvements relates to the correlation betweenthe intensity and quality of the light that enters the camera, and theactinic sensitivity of the film, on the one hand, and the effectiveshutter speed and lens aperture, on the other hand.

In my aforementioned pending patent application, I have pointed out thedesirability of employing an objective lens of fixed aperture,specifically corrected for the zonal aberrations correspon-fling to thataperture. It may under certain circumstances be desirable to replacesuch a lens, in its entirety, by another lens of different fixedaperture, similarly specifically corrected. The present inventionprovides for such a contingency.

Also, notwithstanding the desirability of -using a lens of fixedaperture, it may be desirable, under certain circumstances, to employ alens of variable aperture, and the present improvements relate, in part,to ameans for permittingthe use of such a lens.

I achieveAthe foregoing objects and such other objects as mayhereinafter appear cr be pointed out, in the manner illustrativelyexemplified in the accompanying drawings, wherein- Figure 1 is a generalcross-sectional elevation through a camera embodying the presentimproved features;

Figure 2 is a cross-sectional plan view taken substantially along theline 2-2 of Figure 1;

Figure 3 is a cross-sectional view taken substantially along the line3-3 of Figure 1;

Figure 4 is a cross-sectional view taken substantially along the line 44 of Figure 1;

Figure 5 is a perspective View of the device for locking the filmcassette in position;

Figure 6 is an enlarged fragmentary cross-sectional view takensubstantially along the line 5 6 of Figure 1;

Figure 7 is a fragmentary cross-sectional View taken substantially alongthe line 7 1 of Figure 6;

Figure 8 is a fragmentary cross-sectional view taken substantially alongthe line 8 8 of Figure 6;

Figure 9 is a fragmentary cross-sectional view of the lower portion ofFigure 1 showing the parts in position immediately after vthe shutterhas been released;

Figure 10 is a View similar to Figure 9 showing the parts in positionafter the shutter has been restored and after the automatic filmadvancement;

Figure 11 is a side elevation, partly in section, of the film cassetteby itself;

Figure 12 is a cross-sectional view taken substantially along the lineI2-I2 of Figure 11;

Figure 13 is a view similar to the right hand portion vof Figure lshowing a modification;

Figure 14 is an enlarged cross-sectional view taken substantially alongthe line lll- I4 of Figure 13;

Figure 15 is an enlarged fragmentary view of the upper right handportion of Figure 1;

Figure 16 is a cross-sectional view taken substantially along the lineIii-I6 of Figure 15;

Figure 17 is a plan view taken substantially along the line I1-l'l ofFigure 1;

Figure 18 is a diagrammatic view of the electric circuit with the partsin one illustrative adjustment;

Figure 19 is a view similar to Figure 18 with the parts in anotherillustrative adjustment; and

Figure 20 is a perspective view of the present camera body with the filmcassette in spaced relationship.

The camera illustrated herein is in most respects substantially the sameas that illustrated and described in my aforementioned pending patentapplication. The camera body is preferably of substantially rectangularshape having the front wall 2|), the top wall 2|, the side walls 22, anda bottom wall 23. The rear Wall 24 extends downwardly for only a shortdistance, thus leaving a rear rectangular opening for the reception ofthe lm magazine or cassette. The camera body may thus be said to have acompartment into which the film cassette is removably insertable.

In the front wall 20 of the camera there is an opening 33 behind whichthe objective lens is mounted. Near the top there is a multiple windowconsisting of a series of minute convexities or lenses |150. This windowis intended to receive and transmit a beam of light from the objectWhich is to be photographed.

Accessible through the top Wall 2| is a control wheel 35, or itsequivalent, for regulating the effective shutter speed.

A control wheel 36 'is mounted in screwthreaded relation on the lensassembly, and a portion of this wheel is accessible in at least one ofthe side walls 22, thus permitting exterior control of the movements ofthe objective lens for focusing purposes.

Accessible in the bottom wall 23 of the camera body is a button 93, orits equivalent, which controls the actuation of the shutter.

The functioning and purposes of these various control wheels and deviceswill become apparent in connection with the more detailed description ofthe several parts of the camera, which is to follow. It is to beunderstood that, in each case, unless otherwise specified, these detailsare given merely by way of example, and it will also be understood thatthe various elements entering into the present construction, includingthe various lenses, are all mounted and supported in any convenientmanner by brackets and frames, and equivalent known structural elements,lbut may not be in each case specifically described. Also, where thepresent construction is substantially the same in nature, mode ofoperation, and function, as that which is illustrated and described inmy aforementioned pending patent application, only a brief descriptionwill be given herein.

Thel objective lens This lens (which may be a composite assembly ofindividual lenses, as is customary) is preferably mounted inacylindrical sleeve llf which is externally threaded and engaged by thecontrol wheel 36. A pin |66, mounted in a fixed bracket |61, rides in alongitudinal groove in the sleeve 46, so that rotation of this sleeve isprevented when the wheel 36 is rotated. In thisway, rotation of thewheel 35 advances and retracts the objective lens with respect to theopening 33, for focusing purposes.

In my aforementioned patent application, and also in the embodimentillustrated in Figure 13 of the present drawings, the objective lens hasa fixed predetermined aperture. In the embodiment illustrated in Figure1, and associated figures of the present drawings, a variable apertureor diaphragm is associated with the lens. This may be of any usualconstruction, and may be associated with the lens assembly in anydesired usual manner. Its details are therefore not herein illustrated,and it will suffice to point out that a control wheel |53, concentricwith the control wheel 35, is independently rotatable to vary thediaphragm opening or aperture.

The ylm magazine o1- cassette Some of the novel features of the presentinvention relate to the structural nature, and mode of operation, of thelm cassette. This cassette is shown by itself in Figures 11, 12 and 20,and certain details are shown most clearly in Figures 1, 2 and 3.

It will be understood that the camera. is intended to be used With afilm whose resolving power is comparable with that of the opticalsystem. Such film is loaded into the cassette by the manufacturer orother professional service organization, thus assuring the use of thebest and most proper kind of film, and its proper development andtreatment after exposure. It is intended that the present film cassettebe entirely self-contained and light-tight, capable of separatemanufacture and handling, entirely independent of the camera body, sothat it may be removably insertable, bodily, into the camera. This notonly avoids all possibility of inadvertent exposure of the film duringits loading and unloading with respect to the camera, but also obviatesthe necessity for cumbersome loading and unloading manipulations by thephotographer, and thuscontributes to the ease of use of 'the presentcamera.

Like the camera body, the film cassette is preferably of rectangularshape having the front wall 25, the top Wall 26, the bottom wall 27,side walls 28 (one of which is preferably removable), and Aa rear wall29. This rear wall serves to complete the rear wall of the entire camerawhen the cassette is in position as shown in Figures 1 and 2.

The handling of the cassette is preferably accomplished by finger grips3|) which fit into corresponding recesses in the side walls 22 of thecamera. When the cassette is inserted into the camera to the properextent, and is in accurate predetermined position, it is locked intothis position in the manner presently to be described.

In the front wall 25 of the film cassette I provide an opening 4Q,preferably square, through which may pass the image formed by theobjective lens.

Extending longitudinally through the front Wall 25 is a slot |59 Withinwhich a sliding shield |70 is mounted. This shield has an opening Ilsubstantially the same size and shape as the opening di). It also isprovided with an elongated opening lf2. By means of a compression spring|13 bearing constantly upon a projection 'ifi carried by the shield|12), the latter is maintained normally in the position shown in Figures11 :and l2. In this position the end edge |75 of the shield issubstantially flush With the bottom wall 27 of the cassette, while oneend edge of the opening |12 (the upper edge of this opening as viewed inFigures 11 and 12) projects slightly across a transverse opening 2|9 inthe Wall 25. Also, the opening @D is completely covered, the cassettebeing thus normally in a completely sealed lighttight condition.

Referring now more particularly to Figures 1 and 11, it will be observedthat within the `cassette is mounted the relatively small supply orfeeding reel 41 and the relatively large take-up reel or drum 48. Alength of film 49 travels `from one reel to the other, and in doing soit passes in front of a guide plate 58, against which it is pressed by aguide plate 5| which is constantly under the urgence of springs 52 andunder `the guidance of pins 53. The element 5| is `provided with anopening which is in alignment with the opening 40.

Also contained within the cassette is a motor for advancing the lm fromone reel to another. I have illustratively shown this motor in the formof a spring motor |16, which may be of any suitable construction, suchas that used, for example, in phonographs. This motor is energized orwound up during the course of loading the cassette. It constantly triesto rotate the take-up reel 48 in the direction of the arrow shown inFigure 1. It is restrained however by virtue of the fact that the gearteeth |11 mounted on the take-up reel 48 mesh with the gear |18, thelatter being mounted on the same shaft with a pinion |19 in engagementwith the rack |88. This rack is mounted for reciprocal movement in asuitable guide 18|. Its free end |82 projects through the transverseopening 2|9 in the wall 25, and is provided with a notch with which theshield engages, as shown most clearly in Figure 11. More particularly,the upper end edge of the opening |12 is pressed' down into the notch bymeans of the compression spring |13. The inability of the rack |89 tomove toward the right (as viewed in Figure 1) prevents the spring motor|15 from rotating the take-up reel 48.

In order to limit the speed of action of the motor, when it is freed inthe manner presently to be described, some sort of governor ispreferably associated with it. By way of illustration I have shown aretarding device in Figure 1, designated generally by the referencenumeral |83. This may be any conventional type of device, and I haveshown the kind in which, by means of a gear chain constantly engagingwith the gear teeth |11, a vaned device is rotated, at a rapid speed,the air resistance serving as the retarding inuence.

It is to be observed that the shield |19, which may be of any suitablethin opaque material, is entirely independent of the film 49 and of thefilm guiding means. Accordingly, at no time does the iilrn itself enterinto the function of shielding those portions of it which are not inalignment with the opening 40. The nlm is thus subjected to no frictionat all, at any time, except along its edges.

Inserting the j'lm cassette When the cassette is inserted into thecamera, the side walls 28 t snugly between the side walls 22 of the`camera body, the bottom wall 21 rides over the bottom wall 23 of thecamera body, and the tcp wall 26 slides beneath the interior wall |84mounted within the camera body. The inward movement of the cassette .islimited by the abutment wall |85 and the bracket or bearing |85, andwhen the cassette is properly positioned, the film 49 is exactly thecorrect predetermined distance from the objective lens of the camera,and the opening 49 is accurately in alignment with the principal axis ofthe cameralens.

It is locked in this position by the application of a clip or device ofthe character shown in Figure 5. This device consists of a U-shapedstrip, preferably of metal, having the base |81 and the side arms |88.Carried by the base |81 is the rigid tongue |89. The tongue is insertedupwardly through a suitable slit in the bottom wall 23 of the camerabody, and the arms |88 frictionally engage the opposite side walls 22 ofthe camera body, prefer-ably fitting into shallow recesses `provided forthis purpose. The slit in the camera body is accurately in alignmentwith the slit |69 in the film cassette. Accordingly, the tongue |89presses upwardly against the edge |15 of the shield |18 and presses thisshield into the `position of Figure 1, against the action of the spring|13. This does various things. In the rst place, the upper edge of theshield |10 projects upwardly through a slit in the interior partition|84, thus locking the film cassette firmly in proper position within thecamera body. In the second place, the opening |1| aligns itself with theopening 40, thus uncovering the latter. In the third place, the notch inthe rack |88 is released, thus freeing the rack from restraint by meansof the shield |18.

t may be pointed out that the withdrawal of the cassette from the camerais eiected by a reverse procedure. The mere `removal of the device ofFigure 5 allows the shield |18 to return to its normal position, and thecassette is then readily removable as a complete self-containedlighttight unit.

The shutter The shutter and the parts associated with it aresubstantially as shown and described in my aforementioned patentapplication. Briefly, the preferred construction comprises the twoangularly related opaque wall portions 15 and 16 with a slit 11 arrangedbetween their adjacent edges. The shutter is adapted to pivot around thepin 89 between the starting position shown in Figures 1 and 10, and theend position shown in Figure 9. Movement in one direction is preferablylimited by the stop or abutment 8|, and movement in the other directionmay be conveniently limited by the stop or abutment 82.

The shutter operates under the action of a compression spring 83 whichpresses at the top against one end of the lever 84.

Under normal conditions, the shutter is held in the starting position bythe free end of t-he lever 99 which rocks on the xed pivot 9| and isarticulated at its other end to the rod 92 extending down through thebottom wall 23 cf the camera and terminating in the button 93. A spring94, and a stop pin 95, hold the lever 98 in its normal position.

When the shutter is to be actuated, pressure upon the button 93 allowsthe spring 83 to swing the shutter into the position shown in Figure 9.'The restoration of the shutter to its starting position is accomplishedby the arm |94, which is normally in the position shown in Figures 1 and9, and which is adapted to move into the position of Figure 10 (pivotingat |99) during the restoration of the shutter.

The shutter details, its mode of operation, and its inode ofrestoration, are more fully illustrated and described in myaforementioned patent application.

Automatic film advancement Reference is now directed to Figures l, 6, 7,8, 9, and 10. Mounted in the bearing |86, in alignment with the rack|89, and extending into the aligned bearing 19|, is the rod |92. It isprovided with a notch |93, and with a laterally projecting pin |94adapted to move in a slot in the bearing |9|. A normally-untensionedcompression spring |95, weaker than the nlm motor, bears against the rod|92 at the right (as viewed in Figures l, 9, and 10). Movement towardthe right is positively prevented, under normal conditions, by means ofthe linger |96 (Figure 8) engaging within the notch |93. This nger ispivoted at |91. A spring |98 constantly urges this finger into thefull-line position of Figure 8, at which time it rests against the stoppin |99. Movement is however permitted into the dotand-dash position ofFigure 8.

The rod 92 has a forked portion (see Figure '7) which permits passagethrough it of the rod |92.

Pivoted in this forked portion is the latch 209.

It is pivoted as at 29|, and is constantly urged against the abutment292 by the compression spring 293.

When the button 93 is pressed upwardly, the latch 299 yields as itbrushes past the rear end of the finger lever |99. On the returnmovement of the rod 92, however, under the action of the spring 94, thelatch 299 forces the Iinger lever |95 into the dot-and-dash position ofFigure 8. Ihe rod |92 being thus released, it is free to move under theimpulse of the rack |99, as indicated in Figure 10. During thismovement, the spring |95 becomes compressed, the pin |94 (through theintermediary of the forked arm 294) actuates the shutter-restoring arm|94, and the take-up reel 4B rotates to advance the film.

It will be observed, however, that the pinion |19 has a toothless ormutilated portion 295. By virtue of this toothless portion, engagementbetween the pinion |l9 and the rack |30 is presently destroyed. Thispermits the spring |95 to function, as a result of which the rod |92 andthe rack |39 are forced back into the position of Figure 9. The finger|96, under the urgence of the spring |93, snaps back into the full lineposition of Figure 8, and thus again locks the rod |92 against movement.This in turn again restrains the driving motor |78.

The rack |36 has a constant throw or movement, which is just suiiicientto allow the motor |16 to move the next adjacent unused portion of thelm 49 into receptive positions in alignment with the opening 49. Aspointe-d out in my pending application, the arc through which the reel48 is thus advanced, in stepwise manner, is preferably selected so thatit is unevenly divisible into 360. This is desirable, because of therelatively large diameter of the reel 48, as pointed out in said pendingpatent application, and it will be understood that in the presentcamera, markings on the reel 49, adapted to show through suitable sightopenings, are intended to be provided, although they are not shown indetail in the present drawings.

The Optical viewing system This system is substantially the same as thatwhich is shown and described in my pending patent application. Brieiiy,before the shutter is actuated, the rays of light entering through theobjective lens are reected, as at Hi), to produce an aerial imagesubstantially in the plane of a frame ||2 whose opening is identical inshape and size with the shape and size of the lm portion ultimately tobe exposed. By means of suitable lenses ||3-||6, constituting a sort oftelescope, whose axis turns through 90 by Virtue of a. reflector anobserver is enabled to obtain a magnified view of the aerial image. Hethus sees exactly what the lens of the camera. seesf and by manipulationof the wheel 36 he is enabled to bring the image accurately into focus,and also accurately to frame the picture he intends to take.

The frame ||2 is so positioned with respect to the camera lens that theplane in which the aerial image is formed is exactly the same opticaldistance from the camera lens as the film 49, when the cassette isproperly locked in the camera body. Accordingly, when the aerial imageis in focus, the image that will be thrown onto the film, when thepicture is taken, will also be One way of varying the eiective shutterspeed is by varying the tension of the spring 93 and I have chosen toillustrate such an arrangement in the present drawings. It will beunderstood, however, that the effective shutter speed may be varied inother ways, for example, in the manner shown in Figures 16 and 17 of mypending patent application.

The spring 83 is normally tensioned, so that the shutter is always inreadiness for the taking of a picture. This tension is subject toadjustment, however, by up and down movements of a link |33, the lowerend of which is pivotally articulated to the end of the lever 94opposite to the end which presses upon the spring 83, the lever 84 beingmounted for rocking movement around the pivot |34, The upper end of thelink |33 is pivotally secured to a gear |59 meshing with a pinion |25,the latter being coaxially mounted with respect to the wheel 35.Rotation of the wheel 35 thus controls the tension of the shutter spring83. For example, if it is rotated clockwise, as viewed in Figure l, itlifts the link |33 and increases the tension of the spring 83. If it ismoved counterclockwise, it relaxes the tension of the spring 83.

Shutter spring release This construction affords a convenient means forrelaxing thetension of the shutter spring 83, almost completely, duringrelatively prolonged periods when the camera may not be in use. Thiswould be accomplished by rotating the wheel 35 in a counterclockwisedirection, as viewed in Figure 1. With this purpose in view, an opening2|6 is provided in the side wall of the camera body, and a suitablemarking 2|'| is provided on the outer face of the gear |59, sopositioned that it will show through the opening 2H:` when the shutterspring 83 is relaxed to the maximum allowable degree.

This relaxing of the spring, however, does not in the least aiect theautomatic quality of the camera, since the latter continues to be incomplete readiness for the taking of a picture, during which time theoperator will, in any event, be rotating the wheel 35 pursuant to theimage that he is Viewing.

The electric circuit The composite window, made up of the multiplelenses |40, is substantially the same as that which is described andillustrated in my pending application. Each of the lenses |49, inconjunction with a suitably constructed mask Uil, is so designed thatthe eld of view of the composite window is exactly the same (except forparallax) as the restrictedeld of view which is imposed upon the ilm.

Behind the window is a photo-electric cell |43 which is not illustratedin detail, since such a cell is well known per se. By means of anelectric circuit, most clearly illustrated in Figures 18 and 19, thecell |43 is connected with a device |46, which is an electric meter,known per se, which controls the movements of a movable pointer |41.This pointer moves by varying amounts, in proportion to the intensity ofthe light acting on the photo-electric cell |43.

The pointer |41 is arranged to form part of the image that is producedby the objective lens and viewed by the operator. Preferably, thepointer |41 is arranged in alignment with or closely adjacent to theplane in which the aerial image is produced, as indicated in Figure 17.In this figure I have shown the preferred mode of providing the frame||2 with a xed marker |43 having a predeterminedpositional relation tothe pointer |41 when the settings of the camera (effective shutter speedand lens aperture) are most advantageous with respect to the quality ofthe light emanating from the subject.

In the electric circuit connecting the photoelectric cell and the deviceU46, there is a variable impedance, which I have shown in the form of avariable resistance. This variable impedance has two parts. Thus,referring to Figures 18 and 19, it will be observed that a lead wire 205extends to one end of a resistance 2M, this resistance being relativelymovable with respect to a contact 208 connected, as at 239, with thedevice |43. Another lead wire 2MB extends from the cell |43 to one endof a resistance 2|! which is relatively movable with respect to acontact 212 connected, as at 2|3, with the device m6.

There are various ways of introducing these variable resistances intothe camera assembly. By way of example, I have mounted the resistance281, in the form of a spiral coil, on the gear |58, in concentricrelation to the latter. This is shown most clearly in Figure l, and inFigures and 16. Rotation of the wheel 35 thus serves to introduce moreor less of the resistance 2ST into the electric circuit.

Similarly, I have shown the resistance 2H in the form of a coiled spiralmounted conoentrically on the wheel 2|4 shown most clearly in Figures 1,13 and 14. In the embodiment of Figure 1, the wheel 2M is coaxiallymounted with respect to a pinion 2|5 which meshes with suitable teeth onthe wheel |68. On the other hand, this is not an absolutely essentialinterrelationship of parts, and in the embodiment of Figure 13, thewheel 2|4 is entirely independent. (Although Figure 14 isA based onFigure 13, it serves equally well to depict the wheel 2.14 shown inFigure 1.) In either case, a portion of the wheel 214 projects outthrough the wall of the camera, as shown most clearly in Figure 20, sothat this wheel is accessible from the exterior. Rotation of this wheelintroduces more or less of the resistance 2| into the electric circuit.

Mode of operation It will be observed that the photo-electric cellserves as a means, responsive to the beam of light. transmitted by thecomposite window |49, for controlling the movements of the pointer |41.

It will also be observed that each of the wheels 35 and 2M serves as anindependent means, i. e., independent of the photo-electric device, forvarying the position oi the pointer.

Let it be assumed that the wheel 2M is set in a position whichintroduces a proper predetermined portion of the resistance 2|| into theelectric circuit, with respect to the particular lens that is employedat the moment. Let it also be assumed that alignment of the pointer |41with the iiXed marker |48 is the desired positional relationship ofthese parts for optimum results in taking a picture.

When the camera is then aimed at a subject, the pointer |41 will assumea position depending upon the amount of light emanating from thesubject. The chances are that the pointer will not accurately alignitself with the xed marker |43. The operator brings the pointer to thisposition, however, by manipulating the wheel 35. This serves tointroduce or remove some of the resistance 261, which in turn varies theposition of the pointer. When the pointer is in alignment with the iixedmarker |48, the effective shutter speed is automatically set to thecorrect amount.

For illustration, to bring the pointer to the proper position, using alens of, say, aperture F63, the operator may have to bring the contact268 to, let us say, the full-line position or" Figure 18 on a relativelybright day, and will have to bring the contact to about the dottedposition of Figure 18 on a relatively dull day. The positions shown inFigure 18 are purely illustrative, but serve to indicate that on arelatively dull day less of the resistance 231 will bein the electriccircuit. This resistance is so mounted on the gear |59 that under thesecircumstances the spring 83 is tensioned to a minimum degree, and theeffective shutter speed is thus relatively small, i. e., the exposuretime is relatively long; whereas, on a relatively bright day, more ofthe resistance 201 is in the electric circuit, and the effective shutterspeed is increased by a corresponding greater tension of the spring 83,

Under the same light conditions, but using a lens of larger aperture, itis obvious that the adjustments of the wheel 35 would have to becorrespondingly different. That is, the effective shutter speed wouldhave to be faster (shorter exposure time) in each case. This is takencare of by the resistance 2| For illustration, where a lens of, say,aperture Fl.5 is used, all or most of the resistance 2|! would bewithdrawn from the electric circuit, as shown in Figure 19. Under thesecircumstances, the operators desire to bring the pointer |41 intoalignment with the marker |43 would require that, on a relatively brightday, the contact 233 be brought to about the full-line position ofFigure 19; whereas, on a relatively dull day, it would have to bebrought somewhere in the neighborhood of the dotted position of Figure19.

The resistance 2| i, in effect, shifts the range of movement of thepointer Uil. Assuming, for example, that in Figure 17, the pointer movesin a clockwise direction as light intensity increases, it will movefurther with the resistance 2| out of the circuit (Figure 19) than itwould with some or all of the resistance 2i l in the circuit (Figure18), under the same light conditions.

To harness these eiiects to practical purposes in the present camera, Iprefer to calibrate the wheel 2I4 in terms of' various lens apertures. Ihave indicated this in Figures 1 and l2, in which suitable markingsappear successively on the periphery of one portion of the wheel 2 I4.These markings will show through a suitable window 2 I 8y in the camerabody.

Where, as in Figure 1, the aperture-varier |63 is mechanicallyinterconnected with the wheel 2 i4, an adjustment of the wheel 2|4serves automatically to vary the aperture of the lens and to insert theproper predetermined amount of resistance 2l I into the circuit. Where,as in Figure 13, there is no such mechanical relationship of parts, thevariation in the lens aperture (either by an independent aperture-varieror by replacement of the entire lens) must be accompanied by a separatemanipulation of the wheel 2 I4 in order to bring the correspondingindication to View through the window 218.

There are two ways in which the 'arrangement can be used, in practice.Usually, and preferably, the photographer decides to take a certainpicture with a particular aperture. If the camera is constructed as inFigure 13, he sees to it that a lens having the desired aperture is inthe camera, and he then adjusts the Wheel 2 I 4 until the correspondingmarker shows through the Window 218. Or, if the camera is constructed asin Figure 1, he adjusts the wheel 2M until the desired marker showsthrough the window 2|8, and the desired lens aperture is thusautomatically provided for. I-Ie th'en frames the subject of thepicture, and adjusts the Wheel 35 until the pointer |41 is in thedesired positional relation to the fixed marker |48. The effectiveshutter speed will then have been automatically regulated to the properamount,

On the other hand, the operator may prefer to take a given picture at acertain selected effective shutter speed, in which case he would rst setthe wheel 35 (suitably calibrated in terms of various effective shutterspeeds). He then frames the subject and manipulates the Wheel 214 untilthe pointer l'l is in the desired positional relation to the fixedmarker U58. The indication showing through the Window 2 i8 then tellshim what lens aperture he should use. If the parts are constructed as inFigure l, this lens aperture will automatically be brought intooperation.

It will be understood that the resistances 201 and 2 l i are soconstructed and mounted that the variations effected by the wheels 35and 2l4 Will bring about the desired corresponding effects with respectto aperture opening and eifective shutter speed.

It will also be understood that, ifV desired, the frame H2 may be markedor calibrated so that the operator may, if he chooses, take a picture ofdeliberately under-exposed or over-exposed character, these markingsserving to aid his judgment.

In general, it will be understood that changes in the details hereindescribed and illustrated for the purpose of explaining the nature of myinvention may be made by those skilled in the art without departing fromthe spirit and scope of the invention as expressed in the appendedclaims. It is, therefore, intended that these details be interpreted asillustrative, and not in a limiting sense.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent isl. In a camera, a compartment adapted toreceive a film cassette, a self-contained light-tight lm cassetteadapted to be removably inserted into said compartment; said cassettecomprising within itself a supply reel, a take-up reel, a spring motorfor advancing a lm from one reel to the other, and means normallyrestraining said motor; means for removably securing said cassettewithin said compartment, and means controlled by said securing means forfreeing said motor after the cassette is inserted into the camera.

2. Ina camera, a compartment adapted to receive a film cassette, aself-contained light-tight lm cassette adapted to be removably insertedinto said compartment and provided with anV opening adapted to alignwith the camera axis; said cassette comprising Within itself a supplyreel, a take-up reel, a spring motor for advancing a film from one reelto the other, a movable shield normally covering said opening, and meanscontrolled by said shield for normally restraining said motor; and meansfor moving said shield to uncover said opening and for freeing saidmotor after the cassette is inserted into the camera.

3. In a camera, a compartment adapted to receive a lm cassette, ashutter actuator, a film cassette adapted to be removably inserted intosaid compartment and provided with an opening adapted to align with thecamera axis, said cassette comprising within itself a supply reel, atake-up reel, and a spring motor for advancing a lm from one reel to theother, a movable shield normally covering said opening, means controlledby said shield for normally restraining said motor, means operable fromthe exterior of the camera only after the cassette has been properly andaccurately inserted into said compartment for moving said shield touncover said opening and free the motor, means for releasablyrestraining said motor after it has been freed by said movement of saidshield, and means con-- trolled by the shutter actuator for releasingsaid last-named restraining means so as to free the motor to allow lmadvancement.

4. In a camera, the combination with the elements set forth in claim 3,of means operable upon nlm-advancement for rendering said lastnamedrestraining means operative again.

5. In a camera, the combination of elements set forth in claim 3, saidlast-named restraining means comprising a pinion driven by said motor, atoothed member meshing with said pinion, and a releasable latch lockingsaid toothed member against movement.

6. In a camera, a compartment adapted to receive a film cassette, ashutter actuator, a film cassette adapted to be removably inserted intosaid compartment and provided With an opening adapted to align with thecamera axis, said cassette comprising within itself a supply reel, atake-up reel, and a spring motor for advancing a film from one reel tothe other, a movable sleld normally covering said opening, meanscontrolled by said shield for normally restraining said motor, meansoperable from the exterior of the camera only after the cassette hasbeen properly and accurately inserted into said compartment for movingsaid shield to uncover said opening and free the motor, means forreleasably restraining said motor after it has been freed by saidmovement of said shield, said restraining means comprising a piniondriven by said motor, a toothed member meshing with said pinion, and areleasable latch locking said toothed member against movement, and meanscontrolled by the shutter actuator for releasing said latch so as tofree the motor to allow film advancement.

'7. In a camera, the combination with the elements set forth in claim 6,of restoring means operable upon film advancement for rendering saidlast-named restraining means operative again.

8. In a camera, the combination with the ele- `ments set forth in claim6, of restoring means operable upon film advancement for rendering saidlast-named restraining means operative again, said pinion having atoothless portion, and said restoring means being adapted to reset thetoothed member into latched position when the pinion disengages saidmember by virtue of said toothless portion.

9. In a camera, a compartment adapted to receive a film cassette, aspring-controlled shutter adapted to move out of a set position when theshutter is actuated, a shutter actuator, a film cassette adapted to beremovably inserted into said compartment and provided With an openingadapted to align With the camera axis, said cassette comprising withinitself a supply reel, a take-up reel, and a spring motor for advancing anlm from one reel to the other, a movable shield normally covering saidopening, means operable from the exterior of the camera only after thecassette has been properly and accurately inserted into said compartmentfor moving said shield to uncover said opening and free the motor, meansfor releasably restraining said motor after it has been freed by saidmovement of said shield, means controlled by the shutter actuator forreleasing said last-named restraining means so as to free the motor toallow iilm advancement, and means operable upon lm advancement forresetting the shutter and for rendering said last-named restrainingmeans operative again.

10. In a camera construction, a camera including a shutter, means foroperating the shutter to open the same, means for resetting said shutterand a compartment for receiving a removable cassette, said cassettehaving an opening at one side thereof through which a frame of a stripof film may be exposed, said opening being so positioned that whencassette is in said compartment the opening of said shutter will exposesaid cassette opening and film, a supply reel for a roll of iilm Withinsaid cassette, a talee-up reel for a roll of lm Within said cassette, aspring motor for advancing the iilm from one reel to the other Withinsaid cassette, control means within said cassette to control said motorto prevent movement thereof and allow movement thereof upon actuation toadvance the film a single frame, means to connect said means foroperating said shutter and said means for resetting said shutter Withsaid spring motor control means when said cassette is positioned withinsaid camera so that each operation of said shutter will release saidspring motor to advance said lm a single frame, means Within saidcassette to lock said controlling means to prevent movement of saidspring motor when said cassette is outside said Camera, and movableshield normally covering said opening in said cassette when the cassetteis not in the camera, said shield being provided with means to remove itfrom said opening when said cassette has been properly and accuratelypositioned in said compartment.

1l. In a camera construction, a camera including a shutter, means foroperating the shutter to open the same, means for resetting said shutterand a compartment for receiving a removable cassette, said cassettehaving an opening at one side thereof through which a frame of a stripof film may be exposed, said opening being so positioned that when saidcassette is in said compartment the opening of said shutter will exposesaid cassette opening and film, a supply reel for a roll of lm Withinsaid cassette, a takeup reel for a roll of nlm Within said cassette, aspring motor for advancing the film from one reel to the other Withinsaid cassette, control means Within said cassette to control said motorto prevent movement thereof and allow movement thereof upon actuation toadvance the nlm a single frame, means to connect said means foroperating said shutter and said means for resetting said shutter withsaid spring motor conrcl means when said cassette is positioned Withinsaid camera so that each operation of said shutter will release saidspring motor to advance said iilm a single frame, said last-mentionedmeans including cooperating reciprocatory elements in the cassette andthe camera, means Within said cassette to lool controlling means toprevent movement of said spring motor When said cassette is outside saidcamera, and movable shield normally covering said opening in saidcassette when the cassette is not in the camera, said shield beingprovided with means to remove it from said opening When said cassettehas been properly and accurately positioned in said compartment.

ALVIN H. COHEN.

